To obtain an amino siloxane compound having a hydrogen atom at one terminal silicon and having an aliphatic C-C double bond on the other terminal silicon at good efficiency by subjecting a siloxane compound having a hydrogen atom at one terminal silicon atom and an amine compound having an aliphatic C-C double bond at the other terminal silicon atom to a dehydrohalogeneration condensation.

A silioxane compound of formula I (wherein R1 is an aliphatic C-C-unsaturation-free hydrocarbon group; X is a halogen; and a is 1 or greater) and an amine compound of formula II (wherein R2 to R4 are each an aliphatic C-C-unsaturation-free hydrocarbon group, provided that R2 and R4 may be each H) used in an amount desirably at least equimolar to that of the siloxane compound. It is desirable that pyridine, an amineor the like which traps the hydrogen halide by-produce is added to the reaction system. Thus, a siloxane compound of formula III (wherein R1 to R4 and a are as defined above) can be obtained at good efficiency.